Wireless engine monitoring system with multiple hop aircraft communications capability and on-board processing of engine data

ABSTRACT

An engine monitoring module includes a housing configured to be mounted at the aircraft engine and a first wireless transmitter carried by the housing. A memory is carried by the housing and a processor is carried by the housing and coupled to the memory and the first wireless transmitter and configured to collect and store in the memory engine data relating to at least one engine parameter sensed during operation of the aircraft engine by a plurality of engine sensors that transmit the engine data via the first wireless transmitter. A wireless receiver is located within the aircraft and configured to receive the engine data transmitted from the first wireless transmitter. A second wireless transmitter is located within the aircraft and operatively connected to the wireless receiver and configured to receive and transmit the engine data.

FIELD OF THE INVENTION

This invention relates to real-time monitoring of aircraft engines, andmore particularly, this invention relates to systems and related methodsfor determining an aircraft engine's current performance by collectingreal-time aircraft engine data and processing the engine data for enginemaintenance or other analysis.

BACKGROUND OF THE INVENTION

Harris Corporation of Melbourne, Fla. has designed a system and methodof recording performance of an aircraft engine using a ground data linkunit that interfaces with numerous components of the aircraft, includingthe Digital Flight Data Acquisition Unit (DFDAU), the aircraft DigitalFlight Data Recorder (DFDR), and the data multiplexing system commonlyreferred to as the Full Authority Digital Engine Control (FADEC) forlarger jet turbine engines or the Engine Control Unit (ECU) as sometimesreferred to with smaller jet turbine engines used on smaller aircraft,including turboprops or other engines generating less than 15,000 poundsof thrust. The term “FADEC/ECU” can be used corresponding to either theterm “FADEC” or “ECU” as used by the industry.

An example of this ground data link unit is disclosed in commonlyassigned U.S. Pat. No. 6,047,165, the disclosure which is herebyincorporated by reference in its entirety. An engine monitoring systemusing this ground data link unit is disclosed in commonly assigned U.S.Pat. Nos. 6,148,179 and 6,353,734, the disclosures which are herebyincorporated by reference in their entirety.

In the incorporated by reference '179 and '734 patents, the system andmethod as disclosed can provide a record of the performance of anaircraft engine by collecting engine data during engine operation, forexample, in the ground data link unit, and downloading the collectedengine data over a wideband spread spectrum communications signal to aground based spread spectrum receiver. The signal is demodulated withina ground based spread spectrum receiver to obtain the engine data forfurther processing. It is also possible to upload data to the grounddata link unit, such as algorithms, flight management files, video andentertainment files and other data files.

This Harris Corporation ground data link (GDL) unit is advantageous overprior art systems that took a “snapshot” of basic engine parameters, forexample, when the aircraft had lifted to 1,000 feet after initialtake-off. The data was limited to one snapshot during flight and was notreal-time. These prior art data “snapshots” did not go beyond grossindicators and reactive maintenance techniques. The “snapshots”typically may contain data regarding limited engine parameters (e.g.,N1, N2, EGT and W_(f)) in which the “snapshot” data was recorded either“on board” or downloaded via AGARS using a VHF communication data link.Other monitoring systems required the pilot to enter data manually intoa logbook or required removable media such as flash drives and QuickAccess Recorders (QAR).

The ground data link unit system disclosed in the incorporated byreference '165, '179 and '734 patents overcomes the drawbacks associatedwith the prior art “snapshot,” which never gave a true and complete andfull flight indication of engine performance during flight of theaircraft. Also, these non-GDL prior art monitoring systems as describednot only had data collection of limited value, but also had a high costfor retrieving what may or may not have been the full flight engine datafrom the aircraft because of limited communication options, for example,limited frequencies and narrow bandwidth/spectrum available from the FCCat the aeronautical frequency spectrum. The overly large engine datafiles required high bandwidth, e.g., about 10 kbps up to about 36 MB/FLTHR (without compression), which those non-GDL systems could not deliver.

Although the ground data link unit as disclosed in the '165, '179 and'734 patents is a major improvement over prior art engine monitoringsystems, the disclosed ground data link unit is typically a large unitinstalled on the aircraft and interfaces with many airborne systems aspreviously described. As a result, Harris Corporation developed aWireless Engine Monitoring System (WEMS) module that monitors aircraftengines in real-time without resorting to the larger ground data linkunit that interfaces with many aircraft systems. The WEMS module isdisclosed in commonly assigned U.S. Pat. Nos. 6,943,699; 7,456,756;7,595,739; and 7,755,512, the disclosures which are hereby incorporatedby reference in their entirety.

The WEMS module is an engine monitoring module mounted directly on theaircraft engine. It is not installed in the avionics compartment orsimilar fuselage location, for example, which on the other hand, is thepreferred location for the ground data link unit that connects to manyairborne units. The WEMS module is interfaced in one example to the FullAuthority Digital Engine Controller (FADEC)/Engine Control Unit (ECU) onthe engine. The WEMS module is typically small, in one example, about2×2×4 inches, and can record, store, encrypt and transmit “full flight”engine data. The WEMS module interfaces directly to the FADEC/ECU andrecords hundreds of engine parameters, for example, with a one second orless sampling frequency. It has a preferred conformal antenna and RFtransceiver to download (and upload) data using RF/802.11/cellulartechniques, including other spread spectrum techniques as non-limitingexamples.

This collection and storage of “full flight” engine data using the WEMSmodule allows advanced prognostics and diagnostics on the engine andincreases engine “time-on-wing” (TOW) and decreases engine maintenancecost per hour (MCPH). The WEMS data is downloaded in one example using aRF/(802.11) spread spectrum/cellular signal to an airport server forprocessing and/or transported over the internet, PSTN, cellular or othercommunications network to another workstation for post flight analysis.Data can also be uploaded to the WEMS module, including algorithms foron-board processing. The WEMS module provides an automated wirelesssolution installed directly on the engine, recording full flight enginedata for both large and small turbine engines in large megabyte filesand using a high speed data link to extract.

Although the WEMS module operates as an archival data store for fullflight engine data, it would be desirable to provide the capability todownload in “real-time” significant quantities of engine data duringflight and interface with the communications resources commonlyavailable on most international flights. Additionally, it would bedesirable to use the WEMS module in a cost effective method to detectand diagnose problems with the most mechanically stressed componentswithin a turbine unit of an aircraft engine. This would require precisemonitoring of the rotating subsystems such as the turbine blades andbearing assemblies and gas path parameters such as temperature,vibration, strain and pressure, but would also allow early detection anddiagnosis of turbine component faults and help prevent catastrophicfailures. There are about forty thousand jet engines worldwide thatcould be monitored to determine full flight engine data. Thus, tomonitor the full flight engine data would increase the efficiency andsafety of the engine data.

SUMMARY OF THE INVENTION

In accordance with a non-limiting example, a monitoring system for anaircraft engine includes an engine monitoring module comprising ahousing configured to be mounted on the aircraft engine and a firstwireless transmitter carried by the housing. A memory is carried by thehousing and a processor is carried by the housing and coupled to thememory and the first wireless transmitter and configured to collect andstore in the memory engine data relating to at least one engineparameter sensed during operation of the aircraft engine by a pluralityof engine sensors that transmit the engine data via the first wirelesstransmitter. A wireless receiver is located within the aircraft andconfigured to receive the engine data transmitted from the firstwireless transmitter. A second wireless transmitter is located withinthe aircraft and operatively connected to the wireless receiver andconfigured to receive and transmit the engine data.

In one example, the second wireless transmitter comprises a UHFtransmitter configured to transmit the engine data over an air-to-groundcommunications signal. The second wireless transmitter in anotherexample is configured to transmit the engine data over a satellitecommunications link. The first wireless transmitter in another exampleis configured to transmit the engine data and a data address linked toan identifier of the aircraft engine. A wireless Local Area Network(LAN) is formed within the aircraft to which the wireless receiver andsecond wireless transmitter are connected. In yet another example, aprocessor is located on the aircraft and configured to receive theengine data during the flight of the aircraft and process the enginedata and determine engine operating parameters. Engine operatingparameters can be determined based on the sensed engine data. In oneexample, an engine operating parameter includes a decision for an engineshut down during flight of the aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome apparent from the detailed description of the invention whichfollows, when considered in light of the accompanying drawings.

FIGS. 1-7 are views of the WEMS module and associated components asdescribed in the incorporated by reference and commonly assigned '699,'756, '739 and '512 patents. A description of the WEMS module is givenrelative to FIGS. 1-7 followed by further details of the WEMS moduleused for multiple hop communications, including its use with an EngineWireless Sensor Network (EWSN) and sampling wireless engine sensors atdifferent rates in accordance with a non-limiting example of the presentinvention.

FIG. 1 is a partial fragmentary, isometric view of a jet engine showingthe FADEC/ECU and the WEMS module mounted on the engine, the WEMS moduleinterfacing with the FADEC/ECU for downloading engine monitoring datasuch as disclosed in the commonly assigned and incorporated by reference'699, '756, '739 and '512 patents.

FIG. 2 is a block diagram showing the aircraft engine and aircraft, andthe WEMS module of FIG. 1 interfaced with the FADEC/ECU for downloadingfull flight engine data files and uploading algorithms and other data.

FIG. 3 is a fragmentary, block diagram showing WEMS engine data that canbe downloaded to an airport server and transferred by PSTN, internet orcellular infrastructure to a real-time analysis workstation or otherprocessor.

FIG. 4 is a block diagram showing basic elements of a ground data link(GDL) unit as disclosed in the commonly assigned '165, '179 and '734patents and showing a WEMS module interfaced with the GDL unit.

FIG. 5 is a block diagram showing basic components of a WEMS module asdisclosed in the '699, '756, '739 and '512 patents.

FIG. 6 is a cross-section of an example of a jet engine that generatesengine events to be collected, stored and transmitted from the WEMSmodule.

FIG. 7 is a chart showing various jet engine event reports at enginestart and during flight that could be monitored by the WEMS module.

FIG. 8 is a block diagram of the WEMS module similar to that shown inFIG. 5 and showing greater details of various components in accordancewith a non-limiting example of the present invention.

FIG. 9 is a partial fragmentary view of an aircraft and its engines andshowing an engine mounted WEMS module that wirelessly communicates itsdata to a cabin wireless LAN unit in a first communications “hop” andthen communicates data through a satellite communications link (or byUHF) in a second communications “hop” to an engine service provider(ESP) in accordance with a non-limiting example of the presentinvention.

FIGS. 10-12 are charts showing the market for aircraft engines that cansupport use of the WEMS module in accordance with a non-limiting exampleof the present invention.

FIG. 13 is a block diagram showing a WEMS module that interoperates withan Engine Wireless Sensor Network (EWSN) and Engine Service Provider(ESP) operations center in accordance with a non-limiting example of thepresent invention.

FIG. 14 is a graph showing how the full flight engine data can be usedto maximize the time-on-wing (TOW) for an aircraft engine.

FIG. 15 is a graph showing representative metrics as a non-limitingexample in which airlines can be provided with predictable enginemaintenance operating costs as a non-limiting example.

FIG. 16 is a graph showing derate vs. altitude with percentage ofmaximum climb thrust.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout, and prime notation is used toindicate similar elements in alternative embodiments.

The wireless engine monitoring system (WEMS) as disclosed in theincorporated by reference '699, '756, '739 and '512 patents collectsfull flight engine data and is configured in one example to interoperatewith basic components of the ground data link (GDL) unit as disclosed inthe incorporated by reference '165, '179 and '734 patents. The WEMSmodule is mounted directly to the jet engine and preferably interfaceswith the FADEC/ECU, and downloads data using a wireless communicationssignal, preferably a wideband spread spectrum communications signal, ina similar manner to the wireless ground link-based aircraft datacommunications system disclosed in the '165, '179 and '734 patents. TheWEMS module could also download via any RF connection.

For purposes of technical understanding, the description of the WEMSmodule as set forth in the '699, '756, '739 and '512 patents isdescribed relative to FIGS. 1-7, followed by a more detailed explanationof the WEMS module relative to its multiple-hop communications, use withan Engine Wireless Sensor Network (EWSN) and wireless sensor sampling.

FIG. 1 shows a WEMS module 10 that is mounted directly on the jet engine12 and electrically connected to the FADEC/ECU control unit 14, which isalso mounted on the jet engine. The jet engine 12 shows basic elementsof the turbine 16 and other components. The jet engine cowling/nacelle18 is shown in dashed lines and WEMS module 10 is disposed within thecowling. The WEMS module 10 includes basic functional RF and memorycomponents, such as disclosed in the ground data link unit of the '165,'179 and '734 patents. The WEMS module can be mounted at differentlocations on the engine depending on the type of preferred conformalantenna and the nature of the cowling 18 used in the jet engine.

FIG. 2 shows a basic block diagram of a FADEC/ECU 14 that is operativeas a bidirectional multiplexer for signals to and from the jet engine12. The signals include analog and digital signals and the FADEC/ECU 14gives commands to the engine from the flight deck 20 of the aircraft 22.It also transmits engine status and health signals. Many signals areprocessed by the FADEC/ECU 14, which then transmits the signals over anARINC 429 bus 24 in this non-limiting example at typically 10 kilobitsper second to and from the flight deck 20.

The WEMS module 10 in one example includes a separate data address as anIP address (for each module), which is linked to the serial number ofthe engine. The WEMS module is mounted on the engine and interfaces withthe FADEC/ECU such as through another port on the FADEC/ECU or directlyinto the ARINC 429 bus 24. The radio frequency transceiver capability isbuilt into the WEMS module and is operative for recording, compressingand encrypting full flight data files. It typically will use a conformalantenna 30 that is formed in one example as a small patch antenna thesize of a postage stamp, for example, mounted on a casing 31 that formsa protective housing for the WEMS module 10. Although a conformalantenna is preferred, a separate antenna could possibly be useddepending on the cowling and engine type on which the WEMS module 10 ismounted. A separate antenna could be mounted on a separate location onthe fuselage or other location for enhancing communication.

The WEMS module 10 can use an'archival data store for recording, storingand encrypting and then later transmitting “full flight” engine data.The WEMS module 10 as described in the incorporated by reference '699,'756, '739 and '512 patents can record hundreds of engine parameterswith a preferred one second sampling frequency in one example. The WEMSmodule thus allows advanced prognostic and diagnostic techniques toincrease engine “time on wing” (TOW) and decrease engine maintenancecosts. For example, the WEMS module 10 could be operative with jetengine diagnostic cells, such as used with prognostic and healthmanagement applications, including those designed by ImpactTechnologies, LLC of Rochester, N.Y. The WEMS module 10 can downloadengine data by almost any type of radio frequency signal, includingspread spectrum modulation techniques. The WEMS module 10 could beoperative with cellular, internet, or PSTN communication infrastructuresto download full flight engine data files and upload algorithms or otherdata or programs. Each WEMS module will typically include a separateInternet Protocol (IP) address such that it can be separatelyaddressable for identification and upload and download of data.

FIG. 3 shows a high level block diagram of an aircraft 22 that includesa WEMS module 10 as described in the '699, '756, '739 and '512 patents.The WEMS module 10 downloads engine data and uploads data for onboardprocessing to and/or from an airport server 32, which could be operativewith a communications network 34, such as a public switched telephonenetwork (PSTN), the internet or a cellular infrastructure. The airportserver 32 includes a receiver and transmitter and communicates throughthe communications network 34 to a post flight analysis workstation, forexample, as provided by an engine service provider or other similarprocessor 38 where the engine data can be analyzed to determine the bestmaintenance program for an engine, and thus, extend the time the engineremains on the aircraft without removing the engine. The real-timeanalysis workstation 38 could be directly connected to the airportserver or could receive data directly from the WEMS module 10.

As noted before, the WEMS module 10 can be operative similar to theground data link unit in that it stores data and transmits the datausing a preferred spread spectrum or other wireless communicationssignal. The WEMS module 10 is much smaller, however, and mounts directlyonto the aircraft engine. It has fewer functions than the functionsrequired by a large scale ground data link unit, which is operative withmany aircraft components, including the DFDAU, DFDR and engine sensors.

Referring now to FIG. 4, there is shown a representative example of anoverall communications system architecture for a wireless spreadspectrum data communications system that can be used with the WEMSmodule 10. The architecture in this example has three interlinkedsubsystems: (1) an engine WEMS subsystem 100; (2) a ground subsystem 200(typically airport based but not necessarily at the airport); and (3) aremote engine data control center 300 used for analyzing any downloadedengine data. The WEMS system 100 for one aircraft 22 could include aplurality of WEMS modules 10, each installed on an engine 100 a-d. Twoaircraft 22 and 22′ are illustrated each with respective WEMS modules10, 10′. Each WEMS module 10, 10′ includes an airborne unit (AU) 102,102′, each which includes the processor, transceiver, memory and othernecessary components. Each WEMS module 10, 10′ is operative tocommunicate with a wireless router (WR) segment 201 of the groundsubsystem 200 through a wireless communications link 120. The followingdescription proceeds with reference to one aircraft 22 and WEMS module10 for purposes of description.

The wireless router segment 201 routes the engine data files it receivesfrom the WEMS module 10, either directly to an airport base station 202via a wired Ethernet LAN 207, or indirectly through local area networks207 and airport-resident wireless bridge segments 203 in this onenon-limiting example. The wireless communication link 120 can be aspread spectrum radio frequency (RF) link having a carrier frequencylying in an unlicensed portion of the electromagnetic spectrum, such aswithin the 2.4-2.5 GHz S-band as one non-limiting example. The wirelesscommunication link 120 could also be an RF, internet, cellular, or otherlink.

The ground subsystem 200 in this example includes a plurality of groundand/or airport-resident wireless router segments 201, one or more ofwhich are distributed within the environments of the various airportsserved by the system. A respective ground and/or airport wireless router201 is operative to receive engine data that is wirelessly down-linkedfrom a WEMS module 10. Each ground subsystem wireless router 201 canforward engine data to a server/archive computer terminal 204 of a basestation 202, which can reside on a local area network 207 of the groundsubsystem 200 at an airport or other location.

The base station 202 can be coupled via a local communications path 207,to which a remote gateway (RG) segment 206 is interfaced over acommunications path 230, to a central gateway (CG) segment 306 of aremote engine data control center 300, where engine data files fromvarious aircraft are analyzed. As a non-limiting example, thecommunications path 230 can include an ISDN telephone company (Telco)land line, and the gateway segments can include standard LAN interfaces.Other communications networks, such as cellular, internet, or otherwireless communications can be used. It should be observed that othercommunications media, such as a satellite links or cellular, forexample, may be employed for ground subsystem-to-control centercommunications without departing from the scope of the invention.

The remote engine data control center 300 could include a systemcontroller (SC) segment 301 and a plurality of workstations (WS) 303,which are interlinked to the systems controller 301 via a local areanetwork 305. Engine safety, maintenance, and monitoring analysts are atthe remote engine data control center 300 to evaluate the engine datafiles conveyed to the remote engine data control center 300 from theairport base station segments 202 of the ground subsystem 200. Therespective workstations 303 may be allocated for different purposes.

The system controller 301 can have a server/archive terminal unit 304that preferably includes database management software for providing forefficient transfer and analysis of engine data files, as it retrievesdownloaded files from the ground subsystem. As a non-limiting example,such database management software may delete existing files from a basestation segment's memory once the files have been retrieved.

As described briefly above, and as diagrammatically illustrated in FIG.5, each WEMS module 10 can include a housing and bidirectional wireless(radio frequency carrier-based) subsystem containing a processing unitsuch as a microprocessor 132 and associated memory or data store 134,serving as both an archival data store 134 a and a buffer 134 b forcommunications, including packet communications. The memory 134 iscoupled to the FADEC/ECU. Processing unit 132 can receive and compressthe engine data and store the compressed data in its associated memory134. A report can be generated by the processing unit 132, whichincludes many items of engine data.

The engine data and reports can be downloaded via the RF transceiver 136and its preferred conformal antenna 30. To provide bidirectional RFcommunication capability, the transceiver 136 is operative with thewireless router 201 for upload and download of data.

If the RF communication link is spread spectrum, and a preferred 802.11link, each of a plurality of sub-band channels of an unlicensed 2.4-2.5GHz S-band segment of interest in this non-limiting example can beavailable and preferably used. Other unlicensed or licensed bands couldbe used. A wireless router 201 could continuously broadcast aninterrogation beacon that contains information representative of theemitted power level restrictions at an airport. Using an adaptive powerunit within its transceiver, the WEMS module 10 could respond to thisbeacon signal by adjusting its emitted power to a level that will notexceed communication limitations imposed by the jurisdiction governingthe airport. The wireless (RF) transceiver 136 then accesses the enginedata file stored in memory 134, encrypts the engine data and transmitsthe engine data file via a selected sub-channel of the wireless groundcommunications link to a wireless router 201.

The recipient wireless router 201 forwards the data file to the basestation segment temporarily until the file can be automaticallytransmitted over the communications path 230 to the remote engine datacontrol center 300 for analysis. Further details of the associatedcomponents are described in the above-identified and incorporated byreference patents.

The wireless engine monitoring system (WEMS) as described in the '699,'756, '739 and '512 patents uses similar components as in the GDL unitdescribed in the '165, '179 and '734 patents, but has reduced size andfunctionality for interfacing with the FADEC/ECU and mounting on theengine. The WEMS module is installed on the engine typically under thecowling and in a location to give the best antenna and transceiverfunctionality, but preferably adjacent or near the FADEC/ECU. It ispossible to incorporate the WEMS module with the FADEC/ECU. The WEMSmodule records, stores, encrypts and transmits “full flight” engine dataand in one example interfaces directly to the FADEC/ECU. It can recordhundreds of engine parameters with one second sampling frequency as anexample and is a miniaturized module with a conformal antenna. Itacquires “full flight” engine data and allows advanced prognostics anddiagnostics techniques either on-board or preferably at a remoteworkstation to increase engine “time on wing” and decrease enginemaintenance costs. It is an automated wireless solution installeddirectly on the engine and records full flight engine data for largeturbine engines and results in large megabyte files using the high speeddata link as described before. It is an improvement over those systemsthat record only a few engine data “snapshots,” resulting in limiteddata and limited analysis.

For purposes of reference, a jet engine is described with reference toFIGS. 6 and 7 on which the wireless engine monitoring system (WEMS)module 10 as described in the '699, '756, '739 and '512 patents can beused. Each engine can have one engine mounted WEMS module and each WEMSmodule can have a specific data address, such as an Internet address orother IP address, to allow service providers to access the WEMS moduleand its data in near real-time and perform “intelligent” maintenance.This address is linked to the engine serial number and will be used tostore routine and critical engine information. Use of the WEMS modulecan thus reduce engine maintenance cost per hour (MCPH).

FIG. 6 illustrates one cross-section of a jet engine indicated generallyat 400, showing basic components and engine air flow FADEC/ECU control402 to and from the jet engine that can be used for real-time monitoringof engine events. These events could be downloaded during the firstminute or so of initial take-off to a remote engine data control center300 or saved to memory in the WEMS module and later downloaded todetermine if “on wing” engine maintenance is warranted at thedestination.

For purposes of clarity, reference numerals to describe this jet enginebegin in the 400 series. As shown in FIG. 6, the engine air flowFADEC/ECU control 402 could include the core compartment bleeding; sumppressurization; sump venting; active clearance control; low pressure andhigh pressure recoup; and venting and draining functions. Thesefunctions could be monitored through basic FADEC/ECU control system 402,as known to those skilled in the art. The engine example in FIG. 6corresponds to a General Electric CF6-80C2 advanced design with aFADEC/ECU or PMC control having an N1 thrust management and common turbomachinery. Although this jet engine is illustrated, naturally othercontrol systems for different jet engines could be used, as known tothose skilled in the art.

The engine as illustrated has six variable stages and a ruggedized stageone blade with a low emission combustor and 30 pressurized nozzles andimproved emissions. It has a Kevlar containment to give a lowercontainment weight and a composite fan outer guide vane. It has anenhanced High Pressure Turbine (HPT) with a stage of one blade materialand advanced cooling and active clearance control.

The fan module includes an aluminum/Kevlar containment 404 and a 93-inchimproved aero/blade 406. It has compositive outer guide vanes 408 withan aluminum/composite aft fan case 410 and a titanium fan frame 412 forreduced losses. It additionally has a four stage orthogonal booster 414and a variable bypass valve (VBV) between the fan struts (with 12locations) 416. The engine includes a compressor inlet temperature (CIT)probe 418.

The high pressure compressor includes an IGV shroud seal 420 and a bladedovetail sealing 422 with a trenched casing of stages 3-14 424. Thecompressor includes a vane platform sealing 426 and a short cord stage 8low loss bleed system 428 and improved rubcoat reduced clearances 430.

The compressor rear frame includes a combuster 430 and ignitor plug 432with a fuel nozzle 434 and outer guide vane 436. It includes a vent seal438 and 4R/A/O seal 440 and 4R bearing 442 and 4B bearing 444. It alsoincludes a 5R bearing 446 and 5R/A/O seal 448, a diffuser 450 andpressure balance seal 452. The compressor rear frame also includes astage 1 nozzle 454.

The high pressure turbine area includes an active clearance for controlstages 1 and 2, and coated shrouds indicated at 456. It also includesdirectionally solidified stage 1 blades and damped blades 458 and acooling air delivery system. The high pressure turbine includes athermally matched support structure, and an active clearance control andsimplified impingement with a cradled vane support and linear ceiling.The improved inner structure load path has improved roundness control,solid shrouds and improved ceiling. These components are located in thearea generally at 460 of the high pressure turbine area.

Low pressure turbine technology area includes a clearance control 462, a360° case 464, aerodynamic struts 466 that remove swirl from the exitgas and a turbine rear frame 468 formed as a one piece casting.

Many of these components include sensors and structural force sensorsthat generate signals during initial take-off and throughout flight.Signals can be relayed via the WEMS module to an on-ground maintenancecrew and/or separate remote engine data control center having its ownprocessor and data analytics for advanced analysis.

FIG. 7 illustrates components that were monitored during engine start inone example, including the engine hydraulic system, the oil pressure(psi), the engine cut-off switch, oil temperature (deg C.), fuel flow(lb/hr), the N2L and N1L both in percentage terms, oil temperature andEGT, both in centigrade, and W_(f). Some of the ranges are shown on thevertical axis of the graph, while time is shown on the horizontal axisof the graph.

This information can be downloaded via the WEMS module to a ground basedprocessor and a remote engine data control center can determine if onwing maintenance is warranted at the destination station.

There is now described relative to FIGS. 8-16 the WEMS module that canbe used for multiple-hop communication capabilities, for use with anengine wireless sensor network (EWSN) and for sampling wireless enginesensors at different sampling rates. For purposes of description,reference numerals begin in the 500 series. The reference numerals forthe WEMS module 10, jet engine 12, FADEC/ECU control unit 14, jet enginecowling 18, flight deck 20 at the cabin, aircraft 22, ARINC 429 bus 24,conformal antenna 30, and casing 31 (housing) remain the same throughoutthe description with similar reference numerals.

FIG. 8 is a block diagram of the WEMS module 10 similar to that shown inFIG. 5 and showing greater details of different components andsubcomponents that can be used in accordance with a non-limitingexample. The FADEC 14 interfaces with the WEMS module 10 and providespower to a power controller 502 in the WEMS module that interoperateswith a baseband Media Access Control (MAC) circuit 504 and dualWiFi/WiMAX radio 506, which in turn operates as a transceiver inaccordance with 802.11 and 802.16 standards. In one example, it is afirst wireless transmitter that transmits to the flight data asexplained later. This transceiver (radio) 506 could operate with otherstandards, however, to transmit and receive data through the conformalantennas, which in this example, correspond to a transmit (Tx) conformalantenna 32 a and receive (Rx) conformal antenna 32 b. The FADEC 14communicates over the ARINC 429 bus 24 with a processor 510, which inthis non-limiting example corresponds to a system on a chip (SOC) suchas a Holt HI-8582/8583 integrated circuit chip. This chip interoperateswith an interface Field Programmable Gate Array (FPGA) 512, whichinteroperates with an ATA controller 514 and engine data storage 516,for example, a 60 GB flash memory. The interface FPGA 512 interoperateswith a processor as a WEMS host CPU 518, which in turn, interoperateswith the program flash and RAM 520 and the baseband media access controlcircuit 504. An associated Engine Wireless Sensor Network (EWSN) CentralProcessing Unit (CPU) 522 and transceiver 523 can act as aninterrogation unit and receiver for wireless network sensors asexplained below. The transceiver (radio) 523 can transmit and receivedata through conformal antennas, such as the example illustrated attransmit (Tx) conformal antenna 524 a and receive (Rx) conformal antenna524 b.

In this system, no aircraft modification is required and no manualintervention is required after the WEMS module 10 is installed on theaircraft engine. As indicated below during flight, the WEMS moduleacquires, stores and encrypts “full flight engine data” and canautomatically and wirelessly download engine data during flight orpost-flight. In accordance with a non-limiting example of the presentinvention, the WEMS module 10 can acquire significant quantities of dataduring flight and provide global “real-time” downloading of thatacquired engine data such as using a communications protocol inconformance with ARINC 429. This is a technical standard for theavionics data bus used on most higher-end commercial and transportaircraft as a two-wired data bus and data protocol to support anavionics local area network (LAN). It is a self-clocking andself-synchronizing serial data bus with a transmit and receive onseparate ports. The twisted pair wires provide for balanced differentialcommunications signaling.

Each ARINC communications packet typically has a 32-bit value and fivefields, including a parity bit, a sign/status matrix (SSM) to indicatewhether a data field is valid, a normal operation (NO) to indicate thatdata in the word is considered to be correct data; a functional test(FT) to indicate that data is provided by a test source; a failurewarning (FW) to indicate a failure that causes the data to be suspect ormissing; and a no computed data (NCD) to indicate that data is missingor inaccurate. The SSM as a sign/status matrix can indicate the sign ofthe data or other orientation such as north/south or east/west. TheARINC 429 system on a chip circuit 510 such as the Halt integratedcircuits HI-8582 or HI-8583 is a silicon gate CMOS device thatinterfaces a 16-bit parallel data bus directly to the ARINC 429 serialbus 24. The ARINC 429 processor 510 includes two receivers each withlabel recognition, 32×32 FIFO and an analog line receiver. Up to 16labels can be programmed for each receiver.

FIG. 9 illustrates a fragmentary sectional view of an aircraft 22 andtwo aircraft engines 12, each having an engine mounted WEMS module 10 inaccordance with a non-limiting example of the present invention. Theaircraft 22 includes the flight deck 530 having a cabin wireless LANunit (CWLU) 532 that operates as a wireless access point and receivescommunication signals from the WEMS module 10. The CWLU 532interoperates with a satellite communications unit 540 that includes asatellite data unit 542, a low noise amplifier/power amplifier (LNA/PA)544 and high gain satellite communications antenna 546. These componentsform a second wireless transmitter for a satellite communications link.The CWLU 532 also interoperates with a UHF transceiver 550 that can beused for air-to-ground communications such as the older Air-to-GroundRadiotelephone bands used on aircraft. The UHF transceiver also operatesas a second wireless transmitter. Multiple hop communications isillustrated using the WEMS module 10, CWLU 532, and a satellite 554,which communicates with a ground entry point 556 user satellite dishsuch as a satellite receiving dish that receives data for an engineservice provider (ESP) 562. During flight, the WEMS module wirelessconnects to the cabin wireless LAN unit 532 and can download critical“in flight engine safety data” to the ESP 562 or have an on-boardprocessor analyze the data. This data can support FAA ETOPS (ExtendedTwin Operations) for oceanic routes. The satellite communication linkprovides “real-time” engine data transfers and supports critical enginedecisions at the ESP or on-board, including “in flight engine shutdowns” to determine if one of the engines should be shut down. Real-timeanalysis of aircraft engine data can be accomplished at the engineservice provider 562, including performance-based contract reports forengine diagnostics, health and status of an aircraft engine, performanceburns, time on wing and the environmental impact (carbon emissions) oron-board the aircraft. Satellite communications can include differentcommunications signaling and protocols, including Direct BroadcastSatellite (DBS), the Fixed Satellite Service (FSS), Ku, Ka and C bandcommunications.

Alternatively, the UHF transceiver 550 can be used for communications at848-850 MHz and 894-896 MHz as part of the older telephone band that canconnect to the terrestrial ground system. The system as shown in FIGS. 8and 9 allows significant “high value” and “time critical” data to bedownloaded during flight and provides global “real-time” downloading ofengine data. The WEMS module 10 interfaces with resources commonlyavailable on international flights, including the WiFi cabin wirelessLAN unit 532 in accordance with non-limiting examples operating underthe ARINC 763 standard, which applies to servers on board commercialaircraft, allowing a passenger to have an “office in the sky.” Accesscan be provided to the airborne satellite communications that operate inaccordance with the ARINC 741 standard using the satellite data unit 542and other components as described. Airlines can now more closely monitoraircraft engine performance including meeting IAW ETOPS certificationrequirements that apply to twin engine aircraft on routes with diversiontimes more than 60 minutes using one engine and applies on routes withdiversion times more than 180 minutes for airplanes with more than twoengines. ETOPS is the acronym for Extended Twin Operations as defined bythe U.S. Federal Aviation Administration (FAA) and allows thetwin-engine airliners such as an AirBus A300 or Boeing 737 and up toBoeing 787 to fly the long distance routes that were previouslyoff-limits to twin-engine aircraft.

The WEMS data as real-time aircraft engine data allows a flight crew tomake a decision to do an in-flight check-up and if necessary shut downor adjust the engine thrust of an engine. Algorithms can be programmedinto the WEMS module or a processor at the flight deck or at a groundbased ESP to provide the processing to determine engine operatingparameters based on the sensed engine data and determine if an in-flightshutdown should occur if certain engine operating parameters have beenexceeded. Algorithms can be uploaded to the WEMS module even duringflight, allowing the WEMS module to be configurable “on-the-fly.” It isalso possible to populate a request from the flight deck to the WEMSmodule as to what exceedances are to be investigated and processeddepending on environmental or other conditions. For example, it ispossible to configure the WEMS module to download only specificmonitored parameters and data during flight instead of downloading alarge amount of data. The WEMS module is thus configurable as to datacollection, storage and transmission. The WEMS module is configurableand can be programmed by the flight deck or ESP. For example, ifvibration occurs during flight, it is possible to increase the samplingfrequency for various vibration sensors, while reducing the samplingfrequency of other sensors such that more data is collected duringflight concerning vibration statistics.

FIGS. 10-12 show graphs and statistics for the number of aircraftengines worldwide that can use the WEMS module as described. This datagives an example of the relevant market for the WEMS technology.

The WEMS module in one example operates in accordance with the IEEE802.11 or IEEE 802.16 standards and is implemented with a Wireless LocalArea Network (WLAN) 530 at a preferred 2.4 GHz frequency band. It alsooperates in the 3.6 and 5.0 GHz frequency bands. Over-the-air modulationtechniques use the same basic protocol such as defined in the 802.11band 8011g protocols, typically using the 2.4 GHz ISM band, which divideseach of the various bands into channels. For example, the 2.4000 through2.4835 GHz band is divided into 13 channels that are spaced 5 MHz apart,with availability of the channels often regulated by each country. Thus,depending on worldwide geographical location of the aircraft, the WEMSunit can communicate via its radio 506 on different channels and atdifferent powers depending on jurisdictional requirements at thespecific locale. Some of the channels can also overlap depending onlocal requirements. The data frames are typically divided into specific,standardized sections, which include a MAC header, payload, and framecheck sequence (FCS). Different MAC headers and frame control fields canbe used and subdivided into various subfields. These may be modifieddepending on the geographical location of the aircraft and localjurisdictional rule.

The 802.16 is a wireless broadband standard for a wireless metropolitanarea network as a wireless MAN, commercialized under the name “WiMAX”(Worldwide Interoperability for Microwave Access). WiMAX standardizesthe air interface and related functions with the wireless local loop. Itrequires a physical device layer (PHY) and operates with scalable OFDMA(Orthogonal Frequency Division Multiple Access) to carry data andsupport channel bandwidth between about 1.25 MHz and 20 MHz with about2,048 subcarriers. It supports adaptive modulation decoding and anefficient 64 QAM coding scheme. In some instances, 16 QAM and QPSK canbe used. The WEMS module 10 and other associated components of thesystem may include Multiple-in, Multiple-out (MIMO) antennas to providenon-line-of-sight propagation (NOLS) characteristics for a higherbandwidth and a hybrid automatic repeat request (HARQ) for good errorperformance. The MAC sublayer can include a number of convergentsublayers that describe how the wire line technology such as Ethernet,Asynchronous Transfer Mode (ATM) and internet protocol (IP) areencapsulated on the air interface and how data is classified. Theadvanced Encryption Standard (AES) or Data Encryption Standard (DES) canbe used during data transfer for higher security. Various power savingmechanisms can be used, including a sleep or idle mode. The quality ofservice (WS) can be supported by allocating each connection between asubscriber station and base station.

FIG. 13 illustrates how the WEMS module 10 can interoperate in awireless connection with an existing Engine Wireless Sensor Network(EWSN) 600 that is formed by a plurality of different wireless enginesensors illustrated in this example as individual nodes 600 a-f, toprovide precise monitoring of the rotating subsystem such as the turbineblades and bearing assemblies in the aircraft engine, and gas pathparameters such as temperature, vibration, strain and pressure. Althoughonly six wireless engine sensors are illustrated, it should beunderstood that the engine wireless sensor network for one jet aircraftengine can include at a minimum hundreds of such wireless enginesensors. A separate EWSN CPU 522 (corresponding to the EWSN CPU in FIG.8) at the WEMS module 10 can interoperate with the engine data receivedfrom different wireless engine sensors for communications and the sensorprocessor can configure the wireless sensors forming the EWSN to changesampling rates and interrogate sensors through an appropriate wirelesstransceiver that interoperates with each of the wireless engine sensors.The engine data received from the wireless engine sensors can beprocessed as explained above and aircraft components adjusted throughthe FADEC.

The WEMS module 10 not only interfaces to the FADEC 14 as illustrated inFIG. 13, but also to the wireless engine sensors that are configured toform the EWSN 600 and monitor the critical engine parameters. The EWSNtopology can vary from a simple star network to an advanced, multiplehop wireless mesh network. Propagation between the hops and the networkcan be by routing or flooding. As shown in FIG. 13, various wirelessengine sensors include a fuel flow sensor (S_(F)); temperature sensor(S_(T)); pressure sensor (S_(P)); level sensor (S_(L)); accelerationsensor (S_(A)); and vibration sensor (S_(V)). Each of the wirelessengine sensors can include various transducers that are bidirectionaland provide engine control. Each wireless engine sensor forms a wirelessnode that typically includes a sensing mechanism and includes a radiotransceiver and antenna and a microcontroller (processor) and associatedsoftware and an energy (or power) source. This allows real-timedetection and diagnosis for faults that can be alerted to a pilot.

The EWSN 600 interoperates with the WEMS module 10 and provides a costeffective method to monitor, detect and diagnose problems and targetsmechanically stressed components within a turbine unit or othercomponent of the engine. Use of the EWSN 600 also provides anopportunity for data fusion between the FADEC 14 and EWSN data sourcesto automatically and wirelessly forward data to the Engine ServiceProvider operation center 562 for post flight analysis and allowdetection, diagnosis and prognosis of problems occurring withindifferent turbine components. The data obtained from the EWSN 600provides for early detection and diagnosis of turbine component faultsand helps prevents catastrophic failures and allows real-time dataacquisition for valuable engine operational, performance and designinformation. The flight deck 20 can include the cabin wireless LAN unit532 that includes a processor or other CPU 574 for local enginediagnostics.

The WEMS module 10 is beneficial for power generation design such thataircraft turbine designers benefit from data collected during continuousfield operation of their engines. This allows for design improvements inthe safety, reliability and efficiency of future engine systems. Missioncritical networks (MCN) will also be able to explore relatedopportunities for the commercial aviation market based on data obtainedby the WEMS module interoperative with the EWSN 600, which is apotential driver for future electronic enabled airplane healthmanagement (AHM) that is real-time, continuous and proactive. Onebeneficial opportunity is applicable to commercial/military helicoptertechnology with health and usage monitoring systems (HUMS).

Different wireless engine sensors can be used in the engine wirelesssensor network 600. Typically, each wireless engine sensor forms awireless engine sensor node and provides a radio interface and processorcapability. The wireless engine sensors can operate at 600 or moredegrees Centigrade in the harsh environment of the jet turbine engine tomeasure strain, heat and gas. These wireless engine sensors areadvantageous over wired sensors that are difficult, impractical orexpensive and difficult to implement with rotating components thatdamage the wire leads, making wired sensors impractical in an aircraftengine. Some wireless engine sensors use a passive power source becausebattery power is not feasible. These wireless engine sensors aretypically lightweight and conformal for use on different rotating andnon-rotating surfaces and can operate inside the turbine jet engineswithout unbalancing the engine or disrupting the aerodynamics. It ispossible for the wireless engine sensors to measure strain with 50 KHzvariations and operate at even higher frequencies with modal vibrationsthat occur two to about three times the vane passing frequency. In oneexample, the wireless engine sensors are formed from surface acousticwave (SAW) devices that operate in excess of 1,000 Degrees C., thusallowing them to be used for different wireless strain, temperature andsensing applications in severe radio frequency (RF) multipath andDoppler environments. In one non-limiting example, SAW sensors capturethe RF energy from a resonant antenna structure during interrogationsuch as a signal emanating from the transceiver of the WEMS module toexcite the different surface acoustic waves by piezoelectric coupling toa substrate material. Typically the acoustic waves are delayed betweenmetallic reflectors in proportion to the strain experienced at thatinstant when strain is imparted, and thus, the strained sensing isintrinsic to the device. The reflected acoustic wave is re-radiated backinto the RF domain and the now-modulated data signal is received by theremote RF interrogation unit such as by the transceiver at the WEMSmodule and process engine data through any associated EWSN CPU. Anydifferential time delay between the two strain reflectors is computed,for example, at the EWSN CPU in this non-limiting example based on thephase of the received signal. Any time span between the RF “data” andthe “reference” signals is typically about 100-200 nanoseconds and thusa jet engine spinning at a high RPM is frozen in position when the datapoints are collected.

The advantages of the wireless engine sensors as described include thepassive power feature with no complex circuitry failing at hightemperatures together with the wireless technology that is small,lightweight and conformal to minimize the impact on engine performance.

It is also possible to have a passive, wireless engine sensor network600 that uses a microwave acoustic sensor, for example, using acousticwave technology as a bulk acoustic wave (BAW) device, film bulk acousticresonator (FBAR), acoustic plate mode (APL) device, or a surfaceacoustic wave (SAW) device as described above. The SAW devices typicallyhave a layer of metallic electrodes on the surface of the piezoelectriccrystal and operate by transducing the electrical signal toelectromechanical waves that propagate on the surface of the crystal.The piezoelectric crystals form under the application of the electricalsignal. A SAW delay line can be used with input and output structuresformed as a periodic interdigitated transducer (IDT) electrode structurewith several wavelength periodicities. The synchronous operation of theIDT at the surface launches the electromechanical wave that propagatesat, for example, 3×10³ M/S with orders of magnitude slower than thepropagation of an electromagnetic wave in a vacuum.

For this reason, the term “delay line” is also applied to the wirelessengine sensors, typically a few millimeters to sub-millimeters longdepending on frequency of operation from a few MHz to several GHz. Usingan RF interrogating signal from the WEMS module, for example, the deviceis advantageously operating as a passive device. Batteries or otherexternal power sources are thus not required. Different acoustic wavematerials can be used such as quartz, lithium niobate, and lithiumtantalate. Also, different piezoelectric crystals such as langasite canbe used. The interdigitated electrodes used in the wireless enginesensors are typically high temperature and stable materials, forexample, formed as Pt/Rh/Zro₂ electrodes in one non-limiting example.Different wireless interrogation systems can be incorporated in the WEMSmodule, or in a separate controller, which in turn interoperates withthe WEMS module. The systems can include 15-bit coded transducersoperating with CDMA communications technology and frequency-modulatedcontinuous-wave or frequency-step continuous-wave sensors (FMCW orFSCW). A high-Q resonator response provides some system for sensingbased on variation of the resonant frequency.

The wireless engine sensors can also use microelectromechanical systems(MEMS) technology. It is possible to use RF powered LC sensors and hightemperature thermo-couples or even optical sensors. For example, athermo-couple can measure temperatures up to 2,300° C. An RF powered LCtemperature sensor can use a high-K temperature sensitive ceramicmaterial to realize LC tank temperature sensing with a high-Ktemperature sensitive ceramic material. It is an inductively poweredsystem that generates a time varying electromagnetic field where anytemperature data as the resonant frequency is transmitted to a readercorresponding to the WEMS module through an inductive link of itstransceiver in one example. The resonant frequency of the remote readerchanges when the capacitance of the wireless engine sensor changes andresponds to the various environmental variables such as the temperature.A wireless engine sensor can be farmed as a ceramic multilayer capacitorintegrated with a planar inductor that forms the LC resonant circuit.The capacitance of the sensor is a function of the electric constant ofthe sensitive material and the planar configured capacitor has a lineardielectric constant variation with temperature.

The wireless engine sensor could be formed as an inductor with alead-lanthanum-zirconate-titanate (PLZT) ceramic capacitor havingtemperature dependent characteristics. It can include aninductor-capacitor (L-C) tuned electronic oscillator that incorporatesthe temperature sensitive materials with a change in the value of thecapacitance due to the temperature variation translated into modulationin the oscillator frequency. This results in the change in electricfield that affects the frequency of the resonating harmonic response.The transceiver at the WEMS module (or a separate reader deviceinterfaced with the WEMS module) detects the temperature changes bymonitoring the impedance across the terminals of the antenna as part ofa sensor node. It can use a ceramic coated with a conductive layer ofNiCr and a parallel plate temperature sensing element design thatincorporates a thick film high-K temperature sensitive ceramic materialand thick film electrode to make sensor easy to attach and use onrotating components.

Different wireless engine sensors may be formed as a temperature sensor,pressure sensor, vibration sensor, proximity sensor or position sensorwith appropriate signal conditioning circuitry. A communications modulecould implement communications using a BFSK (binary phase shift key)modulation and frequency hopping spread spectrum (FHSS) multiple accesswith a digital data interface, frequency synthesizer, and transmitterand receiver. Microprocessor and programmable logic can be included as acommunications protocol stack implementation. Each wireless enginesensor as a node could transmit its own power capability data in orderto receive power data from one or more other sensor nodes and candetermine an optimum data transmission route through a wireless sensorcommunication network. Typically a data transmission route would bethrough the wireless sensor node or nodes that have the greatest powercapability. Some power routing can be implemented with one of at leastad-hoc, on-demand distance vector routing protocol (AODD), dynamicsource routing (DSR) and global state routing (GSR). Each wirelessengine sensor node could also transmit data representative of itsposition and if in a fixed position that position data will be aconstant. If the wireless engine sensor is located on a rotatingcomponent, then the sensor position would change, and the position datawould be preferably transmitted simultaneously with the sensor data andpower capability data. It is possible to use any received identificationdata to determine if a wireless engine sensor node transmitsidentification data as a member of the network. Each wireless enginesensor node could be assigned a given access time to the network similarto a TDMA system. It is possible to use a vibration-powered generator aspart of the power supply that is driven by engine vibration and convertsmechanical power to electrical power. Different power scavengingmechanisms can be implemented using MEMS technology to make the nodes assmall as possible.

As noted before, the WEMS module 10 includes an EWSN CPU as shown inFIG. 13 that could be remotely configurable by a processor in the WEMSmodule, on the crew or a processor at the flight deck, or by the EngineService Provider operations center 562. The operations center can alsotransmit instructions to the EWSN 600 via the WEMS module to varysampling rates on specific wireless engine sensors. The sampling ratesare programmable for each of the different wireless engine sensors topermit programmable sensor monitoring, provide detection and diagnosisof faults and allow intelligent maintenance for “real-time” monitoringof critical engine parameters using “customized sampling.”

FIG. 14 is a graph showing that the full flight automated engine datacan be used to maximize time-on-wing (TOW). Current generation enginesprovide “hundreds” of parameters and data sampling typically occurs atone second intervals and can result in lower MCPH costs.

FIG. 15 is a graph illustrating representative metrics in which “fixedprice” operating contracts are used and showing an example engineoverhaul cost as a non-limiting example with an established round figureof $1 million as an example only. The different times between overhauland the years and hours with different contract terms are shown as anon-limiting example. This provides airlines with the predictablemaintenance reserve for engine maintenance operating costs to preventexpensive. e.g., on the order of about a million dollars, to minimizeengine overhaul “surprises.” Several engine service providers offer“fixed price” engine maintenance programs with the savings at themaintenance costs per hour, power-by-the-hour and a 10-year LTSA (LongTerm Service Agreement).

FIG. 16 is a graph showing a climb derate benefit.

Use of EWSN in conjunction with the WEMS module provides for improvedmonitoring of reduced thrust take-offs to the minimum required for safetake-off because different wireless engine sensors can be sampled at agreater rate, for example, at take-off and thrust could be adjusted. Onsome occasions when the full thrust would be more than safely requiredsuch as for lower weight flights, long runway or head wind, it ispossible to choose a thrust setting below the full thrust by telling theengines via the FMC (Flight Management System) that the OAT (Outside AirTemperature) is much higher. Temperature control using the EWSN isbeneficial and various take-off tables can be used as assistance.

Typically the exhaust gas temperature (EGT) margin refers to the bufferbetween the engine's normal operating EGT temperature and its maximumEGT, i.e., the temperature at which it must be inspected, overhauled orreplaced. A higher EGT is an indication of the HPC wear that can causecompressor stall. Different variables can be measured such as flowthrough a fuel metering valve, a variable bleed valve, variable statorvein, the fan speed (NO, the core speed (NO, fan inlet temperature, faninlet pressure, the LPC outlet temperature, the combustor staticpressure, the HPT exhaust gas temperature and the core exhaust pressure.Other actuators can be measured including the fuel flow (WF), variablebleed valve (VBV) and variable stator veins (VSV) operation.

Typically the EGT is a primary measure of engine health. The EGT can becompared with the primary engine power indication called the enginepressure ratio (EPR). For example, at full power EPR there is a maximumpermitted EGT limit. Once an engine reaches a stage where it reachesthis EGT limit, the engine requires maintenance. The amount below theEGT limit is the EGT margin and this margin would be greatest when theengine is new or has been overhauled. The EGT margin is a buffer betweenan engine's normal operating EGT temperature and its maximum EGT and thehigher EGT is an indication of the HPC wear that can cause a compressorstall. Engines are rarely used at the full thrust rating and usuallyhave a level of derate for take-off power that reduces the EGT andincreases the EGT margin. Derates at 5% and 10% will reduce EGT andincrease the EGT margin by as much as 36 degrees. Derating can be usedif the aircraft take-off weight is less than permitted maximum take-offweight (MTOW) and a long runway is available or the OATS are relativelylow.

Air frame health management allows in-flight diagnosis and assessmentthrough the integration of the wireless engine sensors, sensoringmaterials and advanced algorithms that reconstruct damage fields andestimate structural durability and remaining useful life. Thesealgorithms could be incorporated within the WEMS module and incorporateadvanced information processing techniques including neural networks,expert systems, fuzzy logic systems, pattern recognition, signalprocessing for spectral analysis and feature extraction and statisticalalgorithms for detection, estimation, prediction and fusion. It is alsopossible to use the EWSN 600 and WEMS module 10 to maintain LRU (linereplaceable unit) fault states that have a gas path impact such asoffset errors in gas path sensors or actuators. This could reduce falsealarms and false ambiguities. The WEMS module 10 as described alsoenables greater control over life limited parts (LLP) such as therotating turbine engine parts that are critical to engine integrity andare difficult to inspect outside the engine. The WEMS module 10 inconjunction with the wireless sensor network 600 provides enginecondition base maintenance (CBM) to optimize engine maintenance costswhile increasing operational performance with advanced fleet managementand removal planning of aircraft engines.

This application is related to copending patent applications entitled,“WIRELESS ENGINE MONITORING SYSTEM AND ASSOCIATED ENGINE WIRELESS SENSORNETWORK,” U.S. patent application Ser. No. 13/489,665 filed Jun. 6,2012, and “WIRELESS ENGINE MONITORING SYSTEM AND CONFIGURABLE WIRELESSENGINE SENSORS,” U.S. patent application Ser. No. 13/489,701, filed Jun.6, 2012, by the same assignee and inventor, the disclosures which arehereby incorporated by reference.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

That which is claimed is:
 1. A monitoring system for an aircraft engine,comprising: a plurality of wireless engine sensors mounted on theaircraft engine and each configured to sense an engine parameter andengine data and transmit wirelessly the engine data and receive enginedata to change the respective operation of the engine parameter sensing;an engine monitoring module comprising: a housing configured to bemounted at the aircraft engine, a first wireless transceiver carried bythe housing, a memory carried by the housing, a processor carried by thehousing and coupled to the memory and the first wireless transceiver andconfigured to: collect and store in said memory engine data relating toat least one engine parameter sensed during operation of the aircraftengine by the plurality of engine sensors and transmit the engine datavia the first wireless transceiver over a wireless communicationssignal; a wireless local area network (LAN) communications unit locatedwithin the aircraft and forming a wireless access point and wireless LANwithin the aircraft, the wireless LAN communications unit including aprocessor and a wireless communications unit configured to receive thewireless communications signal via the wireless LAN and retransmit theengine data received from the engine monitoring module, and saidcommunications unit further configured to receive and process within theprocessor data regarding engine sensor operation of at least one enginesensor and transmit back to the engine monitoring module data regardingengine parameter sensing in the at least one engine sensor, whereinselected ones of the plurality of wireless engine sensors receive thedata regarding engine parameter sensing and change the operation of arespective sensor for a different engine parameter sensing operation;and a second wireless transceiver located within the aircraft andconfigured to receive the engine data via the wireless LAN over awireless communications signal from the wireless communications unit andtransmit the engine data over a wireless communications signal from theaircraft.
 2. The system according to claim 1, wherein said secondwireless transceiver comprises a UHF transmitter configured to transmitthe engine data over an air-to-ground communications signal.
 3. Thesystem according to claim 1, wherein said second wireless transceiver isconfigured to transmit the engine data over a satellite communicationslink.
 4. The system according to claim 1, wherein said first wirelesstransceiver is configured to transmit the engine data and a data addresslinked to an identifier of the aircraft engine.
 5. A method ofmonitoring an aircraft engine, comprising: mounting a plurality ofwireless engine sensors on the aircraft engine and each configured tosense an engine parameter as engine data and transmit wirelessly theengine data and receive data to change the respective operation of theengine parameter sensing; mounting an engine monitoring module at theaircraft engine, said engine monitoring module comprising a housing thatis mounted at the aircraft engine, a first wireless transceiver carriedby the housing, a memory carried by the housing, and a processor coupledto the memory and the first wireless transceiver; collecting and storingin the memory engine data relating to at least one engine parametersensed during operation of the aircraft engine by a plurality of enginesensors; forming a wireless local area network (LAN) within the aircraftby locating a wireless local area network (LAN) communications unitcomprising a processor, a wireless access point and a wirelesscommunications unit within the aircraft; transmitting the engine datafrom the first wireless transceiver of the engine monitoring module viathe wireless LAN to the wireless communications unit and receiving andprocessing within the processor data regarding engine sensor operationof at least one engine sensor and transmitting back to the enginemonitoring module data regarding engine parameter sensing in the atleast engine sensor and transmitting to selected ones of the pluralityof wireless engine sensors data regarding engine parameter sensing andchanging the operation of a respective sensor for different engineparameter sensing operation; and transmitting the engine data via thewireless LAN from the wireless LAN communications unit to a secondwireless transceiver located within the aircraft and transmitting theengine data from the second wireless transceiver over a wirelesscommunications signal from the aircraft.
 6. The method according toclaim 5, and further comprising transmitting the engine data via thesecond wireless transceiver over a satellite communications link.
 7. Themethod according to claim 5, and further comprising transmitting theengine data over an Ultra High Frequency (UHF) communications signal asan air-to-ground communications signal.
 8. The method according to claim5, and further comprising assigning a data address to the enginemonitoring module and linking the data address to an engine serialnumber for tracking the aircraft engine.
 9. The method according toclaim 5, and further comprising receiving engine parameters within theengine monitoring module collected from the plurality of engine sensorsformed as wireless engine sensors configured into an engine wirelesssensor network and transmitting the engine parameters over the wirelesscommunications signal via the wireless LAN to the wireless LANcommunications unit for processing within its processor.